Diphtheria causes a thick coating in the nose, throat, and airways. It can lead to breathing problems, paralysis, heart failure, or death.

Pertussis (whooping cough) causes coughing so severe that it interferes with eating, drinking, or breathing. These spells can last for weeks and can lead to pneumonia, seizures (convulsions), brain damage, and death.

Tetanus (lockjaw) causes painful tightening of the muscles, usually all over the body. It can lead to "locking" of the jaw so the victim cannot open the mouth or swallow. Tetanus leads to death in about 1 out of 10 cases.

Diphtheria and pertussis are spread from person to person. Tetanus enters the body through a cut or wound.

The diphtheria, tetanus acellular, and pertussis pediatric vaccine (also called DTaP) is used to help prevent these diseases in children who are ages 6 weeks to 6 years old (before the child has reached his or her 7th birthday).

This vaccine works by exposing your child to a small dose of the bacteria or a protein from the bacteria, which causes the body to develop immunity to the disease. This vaccine will not treat an active infection that has already developed in the body.

Like any vaccine, the DTaP vaccine may not provide protection from disease in every person.

Your child should not receive a booster vaccine if he or she had a life-threatening allergic reaction after the first shot.

Keep track of any and all side effects your child has after receiving this vaccine. When the child receives a booster dose, you will need to tell the child's doctor if the previous shot caused any side effects.

Becoming infected with diphtheria, pertussis, or tetanus is much more dangerous to your child's health than receiving this vaccine. However, like any medicine, this vaccine can cause side effects but the risk of serious side effects is extremely low.

Get emergency medical help if your child has any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if the child has a serious side effect such as:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report vaccine side effects to the US Department of Health and Human Services at 1-800-822-7967.

What is the most important information I should know about diphtheria, tetanus, acellular pertussis vaccine (Daptacel (DTaP), Infanrix (DTaP), Infanrix (DTaP) Preservative Free, Tripedia (DTaP))?

This vaccine is given in a series of shots. The first shot is usually given when the child is 2 months old. The booster shots are then given at 4 months, 6 months, 15 months, and 18 months of age, and again between 4 and 6 years of age. Your child's booster schedule may be different from these guidelines. Follow your doctor's instructions or the schedule recommended by your local health department.

Be sure your child receives all recommended doses of this vaccine. Your child may not be fully protected against disease if he or she does not receive the full series.

Your child can still receive a vaccine if he or she has a minor cold. In the case of a more severe illness with a fever or any type of infection, wait until the child gets better before receiving this vaccine.

Your child should not receive a booster vaccine if he or she had a life-threatening allergic reaction after the first shot.

Keep track of any and all side effects your child has after receiving this vaccine. When the child receives a booster dose, you will need to tell the doctor if the previous shot caused any side effects.

Becoming infected with diphtheria, pertussis, or tetanus is much more dangerous to your child's health than receiving this vaccine. However, like any medicine, this vaccine can cause side effects but the risk of serious side effects is extremely low.